Time reversal may refer to:
- In physics, T-symmetry - the study of thermodynamics and the symmetry of certain physical laws where the concept of time is reversed — i.e. where a mirror (reverse) transformation is applied to a forward direction time state.
- Time Reversal Signal Processing, a signal processing technique popular in acoustics, and currently being applied to electromagnetics, that results from the reversal in time of a system's response signal
- Time travel, theorised and speculative concepts about travelling physically through time
Famous quotes containing the words time and/or reversal:
“The first in time and the first in importance of the influences upon the mind is that of nature. Every day, the sun; and after sunset, night and her stars. Ever the winds blow; ever the grass grows.”
—Ralph Waldo Emerson (1803–1882)
“Perversity depends on reversal and substitution.”
—Mason Cooley (b. 1927)